1. Technical Field
The present invention relates in general to improved logical volume management and in particular to improved adjustment of storage allocation within a logical volume. Still more particularly, the present invention relates to adjusting the storage space allocated between a file system and its file system log housed in a static logical volume.
2. Description of the Related Art
Most data processing systems include a data management system for managing the storage of files within the physical storage media available to the data processing system. In particular, data management systems may manage the storage of data files in file systems organized within logical volumes. Logical volumes include pages of physical storage media organized to appear as a contiguous data storage device, even though in reality the physical pages are not contiguous. In a file system, a file is traditionally logically subdivided into pages within the logical volume.
In addition, a data management system may implement a file system log that may be stored in the same logical volume as the file system. The log may be used to track changes to file system control data, also called metadata, such as blocks allocated, mapping of file allocation to logical blocks, directory contents, and other file system related data. The log can be used to help maintain consistency when the metadata is changed.
When initializing a logical volume, it is typical to assign a minimum number of physical pages to the logical volume for file system purposes. Then, if the log for the logical volume is stored in the logical volume, the pages assigned to the logical volume are further allocated among the log and file system.
While a file system and log may each be allocated a particular portion of the logical volume, the file system and log may each grow to need storage space larger than the allocated portion. Currently, when the log needs additional storage space, additional physical pages are added to the logical volume for the log. In addition, currently, when the file system size is insufficient, additional physical pages are added to the logical volume for the file system.
While adding physical pages to a logical volume is one way of compensating for underestimated file system and log needs, addition of physical pages is not always available. For example, as is typical, all of the physical pages of the physical storage media may already be allocated among the available logical volumes. Further, it is also typical that either the file system or log may have unused storage capacity, such that when the additional physical pages are added, other pages already allocated to the logical volume remain unused.